Conventional devices of the general type claimed herein include a busbar and a flexible printed substrate, each of which carries a contact section. The current from the power supply goes to the busbar from which it is sent to the various load elements by the substrate, wire harnesses, and the like. A portion of the junction box constitutes a connector holder and the aforementioned contact sections are removably disposed therein. A busbar connector and a printed substrate connector are removably disposed in the connector holder; within the foregoing connectors, contact terminals are arranged to form contacts with the contact sections of the busbar and substrate. An electrical connection can be formed between the busbar and the substrate by separately fitting the busbar connector and the printed substrate connector into the connector holder.
However, such a junction box requires a busbar connector and a printed substrate connector in order to complete the connection between the two. This makes it necessary to have a larger number of parts and increases costs. Furthermore, these elements require space and this must be provided with the junction box, thereby increasing its size. Alternatively, it is possible to eliminate the connectors and solder the two sections together; however, passing these elements through a solder bath is difficult and unsuitable for mass production.